Metallic Needlesare designed for use with metallic thread. They have a large, elongated eye and a grooved shaft so the thread moves through the needle and fabric better. This reduces the heat and friction and results in less thread breaks. They come in the two sizes - 80/12 and 90/14. Because of the abrasion the eye of these needles receive from metallic thread, they have to be changed more frequently than ordinary needles – around every 50,000 stitches. If your metallic thread is fraying then change the needle.